Android Police made fascinating conclusions after peering into the code guts of the app. The mobile wireless service, codenamed Project Fi, will sell data by the gigabyte and charge data above the plan at a flat rate (no overage), with unused data credited back to the account. Domestic calls and texts are free, while international calls come at a low cost, just like with Google Hangouts. The app in question, codenamed Tycho, will let users see their data usage and monitor their account–all the standard stuff from a mobile network’s app, though you can also partially activate, suspend, and reactivate service straight from the app.

As to the legitimacy of the leaked code, Android Police hedges, giving it a 6/10 on believability that it came from Google. But the information syncs up with things we already know: Mobile service will be data-based but will depend on infrastructure from other carriers. The two partner carriers included in the leaked app’s code lines, Sprint and T-Mobile, were previously rumored to be partnering with Google. Verizon and AT&T are conspicuously absent. (Interestingly, Sprint and T-Mobile both endorsed net neutrality, while Verizon and AT&T were vocal opponents.) Google’s plan to piggyback on existing carrier infrastructure ties in with rumors that Google is looking to partner with multinational mobile network Three, which would drive data costs for Google’s international calls down.

Legitimacy of this rumor aside, there are still many unanswered questions. The leaked app is specifically for Android, but which Android phones will Google’s wireless service work on? Will it come to iOS? Where are Verizon and AT&T in this? And, the biggest question: How affordable will it be?